3-(10,11-Dihydro-N,N-dimethyl-5H-dibenz [b,f]azepine-5-propanamine) commonly known as Imipramine is a well-known tricyclic medicant. The hydrochloride salt and Pamoate salt of imipramine are widely used with common names Tofranil and Tofranil-PM respectively. While Tofranil is prescribed as medication for both depression and enuresis, Tofranil-PM is specifically used as antidepressant.
Tofranil-PM, represented by the formula-1 is a dipamoate salt of Imipramine. Considering the potential of Imipramine Pamoate, many methods have been developed for its preparation.

The synthesis described in, U.S. Pat. No. 7,718,649 describes a synthesis of amorphous forms of Imipramine Pamoate from disodiumpamoate with Imipramine hydrochloride in aqueous solution. WO2009/047796 gives the preparation of crystalline form of Imipramine Pamoate using disodium Pamoate with Imipramine Hydrochloride in aqueous solution. U.S. Pat. No. 8,039,461, describes conversion of known forms of polymorphs of Imipramine Pamoate to other polymorphic forms by heating and further processing the product obtained.
It can be noted that aforementioned procedures utilize Sodium Pamoate and water solvent as Pamoic acid is poorly soluble in many of the common organic solvents.
Apart from the methods being tedious the usage of sodium salt of Pamoic acid leads to the contamination of the product with sodium chloride and usage of water may lead to microbial contamination. The methods are also tedious with multiple steps and requires surplus amount of reagents to obtain the target compound. The yield of the target compound is not appreciable making the entire process uneconomical.
In order to reduce the cost of Imipramine Pamoate it is imperative that a simple method with cost effective reagents is proposed. The present disclosure provides an economical method with high yield clearly demonstrating to aid in reduction of the cost of the target compound.